One-pot sausage casserole with garlic breadcrumbs

Name: One-pot sausage casserole with garlic breadcrumbs
Prep time: 10 min
Cook time: 45 min
Total time: 55 min
Cuisine: British, European
Ingredients: 3 tbsp olive oil, plus an extra drizzle (optional); 8 large pork sausages; 1 onion, finely sliced; sprinkle of golden caster sugar; 1 tbsp red wine vinegar; 1 tbsp tomato purée; ½ tsp smoked paprika; 400g can chopped tomatoes; 100ml red wine; 2 bay leaves; 400g can butter beans, drained but not rinsed; 50g fresh breadcrumbs; 2 garlic cloves, finely grated; handful of parsley leaves, roughly chopped